1. Technical Field
The invention relates to a device for compensating the pressure of a liquid in a liquid conduit of an animal drinking trough with a housing which is capable of being inserted into the liquid conduit and in which chambers for inflowing liquid and for outflowing liquid are located, at least one valve arrangement being arranged between the chambers separated by a partition. The invention relates, furthermore, to a method for changing the pressure compensation ratio, in particular of a device for compensating the pressure in a liquid conduit, according to the pressure of the inflowing liquid being changed to a lower pressure for outflowing liquid by means of a valve arrangement having a valve body.
2. Prior Art
Devices of the type referred to here are designated in the specialized jargon as gradient controllers. They are preferably used along inclined liquid conduits for feeding drinking nipples for animals, for example poultry. In the case of inclined liquid conduits, the pressure rises along these. The gradient controllers serve for equalizing the pressure along the inclined liquid conduit.
There are known gradient controllers having a valve arrangement which possesses a spring-loaded valve body. The springs necessary for this purpose often present problems in practice. For example, over a period of time, the springs may fail due to a fracture. The known gradient controllers therefore operate only unreliably.
Proceeding from this, the object on which the invention is based is to provide a device (gradient controller) and a method of the type mentioned in the introduction, by which the pressure along inclined liquid conduits can be adapted according to the conditions in a simple and reliable way.
A device for achieving this object has the features of claim 1. Since the valve arrangement possesses a preferably cylindrical valve pin which closes as a result of its own weight, the spring necessary in the known gradient controllers or gradient pressure controllers may be dispensed with. Moreover, the valve pin ensures that the valve arrangement opens and closes reliably, because said pin, by virtue of its preferably cylindrical shape, can be guided reliably so as to be capable of being moved up and down.
There is provision, furthermore, for assigning the valve arrangement to a chamber for outflowing liquid. The valve pin can thereby by arranged vertically above the chamber of the inflowing liquid. As a result of this, the valve pin capable of being moved up and down can, by its own weight, close the valve arrangement.
According to a preferred embodiment of the invention, the valve pin is provided, preferably on its underside, with a conical, in particular frustoconical, sealing surface. This frustoconical sealing surface matches a likewise conically, in particular frustoconically formed valve seat. A reliable seal is therefore ensured when the sealing surface of the valve pin rests on the valve seat. A gravity-induced reliable closing of the valve arrangement is ensured as a result, specifically even in the case of small valve pins which have only a low own weight.
According to a preferred embodiment of the invention, the guide for the valve pin is longer than the length of the latter. As a result, for scavenging the liquid conduit, the valve pin can be moved sufficiently far away from the valve seat. The gradient controller according to the invention consequently allows unimpeded scavenging of the drinking appliance.
There is provision, furthermore, for providing the guide for the valve pin in sleeve-like insert part which is arranged in a matching sleeve of the housing. Thus, by means of the insert part, the valve pin of the valve arrangement can be taken out of the gradient controller sleeve arranged on the housing, for example in order to clean the valve arrangement. So that the insert part, together with the valve pin, can be mounted and demounted, the valve pin is secured in the insert part against falling out. Preferably, for this purpose, the insert part has spring tongues which, by virtue of elastic deformation, make it possible to separate the valve pin from the insert part when the latter is to be exchanged.
A method for achieving the object mentioned in the introduction has the measures of claim 20. Accordingly, the valve arrangement is provided with valve bodies of different own weight, in order to change the pressure compensation ratio of the gradient controller. In the case of a comparatively heavy valve body, the gradient controller brings about a greater pressure difference between the inflowing liquid and the outflowing liquid. Conversely, a lighter valve body leads to a smaller pressure difference in the chambers connected by means of the valve arrangement.
In the preferred method, the valve body is exchanged together with the insert part. The insert part arranged in the housing of the gradient controller so as to be capable of being pulled out can easily be mounted and demounted.
Alternatively, it is also possible to pull the insert part, together with the valve body, out of the sleeve of the housing and, with the insert part demounted, to exchange the valve body by the latter being separated from the insert part and replaced by a new valve body, in particular a valve pin. The same insert part may always be used when, according to a preferred embodiment of the invention, the different valve bodies or valve pins do not differ in diameter, but only in length.